Field of Invention
This invention relates generally to thermotherapy, and in particular to a localized thermotherapy technique and an apparatus based thereon in which heated air is projected as a high velocity wind toward a limited surface area on the body of a patient in a pulsatory wave pattern causing rapid inward heat transfer to take place toward an internal problem region underlying this area in a manner raising the temperature of the region without, however, causing undue discomfort or injury to the patient.
The term "problem region" as used herein refers to a tumor, a set of muscles, or any other site underlying the skin which is causing difficulty and which lends itself to treatment by hot or cold therapy.
The interior of the human body has a normal temperature level which is usually said to be 98.6.degree. F. But actually, in the course of each 24-hour period, the body temperature rises above or falls somewhat below this nominal value. Body temperature is determined by the relationship existing between the amount of heat internally generated, which depends on basal metabolism and the amount of heat escaping from the body. Additional heat is produced as a result of muscular activity, this being dissipated by an increase in radiation, conduction or evaporation from the skin surface and by more rapid and deep breathing.
If the heat produced by a body surpasses heat losses therefrom, this gives rise to fever; but if heat losses exceed heat production, then the body temperature falls below the nominal value, resulting in shivering and hypothermia.
Medical practitioners since ancient times have known that the application of heat to the body is useful in the relief of muscle soreness and various aches and pains, as well as in the treatment of certain pathological conditions. Thus the use of heat for the treatment of arthritis and other abnormalities is now commonplace. Hot water bottles and electrical heating pads are in widespread use, nor merely to provide warmth, but also to afford a degree of relief or therapy for various conditions. In applying heat to the surface of the body, one may do so by convection, by direct contact with a warmed substance; that is, by conduction, or by radiating energy into the body.
Difficulty has heretofore been experienced in effectively applying heat which is electrically or otherwise generated to a patient. When transferring heat inwardly through living tissue to a problem region underlying the skin, if the heat applied to the skin surface is within a tolerable temperature range, then not enough heat energy is transferred to this site to afford beneficial effects. When, however, the temperature of the applied heat at the skin area is such as to bring about an adequate heat transfer to the problem region, then the skin temperature is usually well above an acceptable level, and this may result in extreme discomfort to the patient and even to the burning of surface tissue.
As pointed out in chapter 10, "Therapeutic Heat" in the text, Therapeutic Heat and Cold by Justus F. Lehmann, published in 1982, it is generally accepted that heat produces desirable therapeutic effect, for it increases the extensibility of collagen tissues, it decreases joint stiffness, and it affords pain relief. Moreover, heat relieves muscular spasms, it aids in the resolution of inflammatory infiltrates, edema and exudates, and it enhances blood flow.
It is also now recognized that by heating tumors to a higher temperature than the surrounding tissue, the tumor may be caused to shrink and disappear. As noted in The New York Times of April 14, 1982 (section C2) in an article on modern approaches to cancer treatment, the effectiveness of heat therapy is based on the fact that cancers have poor circulation and a reduced ability to dissipate heat. "Thus a temperature of more than 113 degrees Fahrenheit could destroy cancer cells while sparing normal tissue." The concern of the present invention is not with the heat treatment of any particular medical condition or problem region, but with a more effective technique therefor.
While the present invention will be described mainly in connection with thermotherapy or hyperthermia, it is to be understood that a technique and apparatus in accordance with the invention is also applicable to hypothermia treatment in which therapeutic effects are gained by cooling an internal problem region.